07:41 AM EDT, 06/18/2026 (MT Newswires) -- Enanta Pharmaceuticals ( ENTA ) said Thursday that it plans to advance its RSV treatment candidate, zelicapavir, into a registrational phase 2/3 trial in high-risk adults following a successful End-of-Phase 2 meeting with the US Food and Drug Administration.

The clinical-stage company said the study will begin in Q4, with topline data expected next year.

Enanta said it also plans to launch a phase 2b trial of zelicapavir in pediatric RSV patients in Q3, with results expected next year.

The company said the pediatric study will be conducted in collaboration with the Penta Foundation and the AMS-PHPT Research Unit at Chiang Mai University.

Enanta said the global market opportunity for an oral RSV antiviral targeting children and high-risk adults exceeds $2 billion.